If you're working on a website and want users to use it repeatedly and form a community on it, you should probably give them a way to create an account and log in to your site. This video will show you how to create an AJAX login script using AJAX with jQuery, which will allow your users to do exactly what I described above, making your website much more professional and a much better place for people to stay and click on ads or whatever else you want them to do.